Chaiwalla doesn't serve an "afternoon tea," but open-faced sandwiches, scones, shortbread, and, of course, tea, are always available on the regular menu.
When I visited Chaiwalla they were closed, so I was only able to get
pictures of the outside of the building.

Photo by Julie Sparks.

From Tea Talk magazine:
Mary O'Brien offers what must be the very best Darjeelings anywhere. A true aficionada, Mary's shop offers chai, an Indian tea "drink" with cardamom, and her tea treats reflect an interest in Himalayan cultures. A must-see. Ask about her Ashley Falls Tea Learning Centre!